/*
** Copyright 2010, The Android Open-Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#define LOG_TAG "alsa_pcm"
//#define LOG_NDEBUG 0
#include <cutils/log.h>
#include <cutils/config_utils.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <linux/ioctl.h>
#include "alsa_audio.h"
#define __force
#define __bitwise
#define __user
#include "asound.h"
#define DEBUG 0
/* alsa parameter manipulation cruft */
#define PARAM_MAX SNDRV_PCM_HW_PARAM_LAST_INTERVAL
static inline int param_is_mask(int p)
{
return (p >= SNDRV_PCM_HW_PARAM_FIRST_MASK) &&
(p <= SNDRV_PCM_HW_PARAM_LAST_MASK);
}
static inline int param_is_interval(int p)
{
return (p >= SNDRV_PCM_HW_PARAM_FIRST_INTERVAL) &&
(p <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL);
}
static inline struct snd_interval *param_to_interval(struct snd_pcm_hw_params *p, int n)
{
return &(p->intervals[n - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL]);
}
static inline struct snd_mask *param_to_mask(struct snd_pcm_hw_params *p, int n)
{
return &(p->masks[n - SNDRV_PCM_HW_PARAM_FIRST_MASK]);
}
static void param_set_mask(struct snd_pcm_hw_params *p, int n, unsigned bit)
{
if (bit >= SNDRV_MASK_MAX)
return;
if (param_is_mask(n)) {
struct snd_mask *m = param_to_mask(p, n);
m->bits[0] = 0;
m->bits[1] = 0;
m->bits[bit >> 5] |= (1 << (bit & 31));
}
}
static void param_set_min(struct snd_pcm_hw_params *p, int n, unsigned val)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
i->min = val;
}
}
static void param_set_max(struct snd_pcm_hw_params *p, int n, unsigned val)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
i->max = val;
}
}
static void param_set_int(struct snd_pcm_hw_params *p, int n, unsigned val)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
i->min = val;
i->max = val;
i->integer = 1;
}
}
static void param_init(struct snd_pcm_hw_params *p)
{
int n;
memset(p, 0, sizeof(*p));
for (n = SNDRV_PCM_HW_PARAM_FIRST_MASK;
n <= SNDRV_PCM_HW_PARAM_LAST_MASK; n++) {
struct snd_mask *m = param_to_mask(p, n);
m->bits[0] = ~0;
m->bits[1] = ~0;
}
for (n = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL;
n <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; n++) {
struct snd_interval *i = param_to_interval(p, n);
i->min = 0;
i->max = ~0;
}
}
/* debugging gunk */
#if DEBUG
static const char *param_name[PARAM_MAX+1] = {
[SNDRV_PCM_HW_PARAM_ACCESS] = "access",
[SNDRV_PCM_HW_PARAM_FORMAT] = "format",
[SNDRV_PCM_HW_PARAM_SUBFORMAT] = "subformat",
[SNDRV_PCM_HW_PARAM_SAMPLE_BITS] = "sample_bits",
[SNDRV_PCM_HW_PARAM_FRAME_BITS] = "frame_bits",
[SNDRV_PCM_HW_PARAM_CHANNELS] = "channels",
[SNDRV_PCM_HW_PARAM_RATE] = "rate",
[SNDRV_PCM_HW_PARAM_PERIOD_TIME] = "period_time",
[SNDRV_PCM_HW_PARAM_PERIOD_SIZE] = "period_size",
[SNDRV_PCM_HW_PARAM_PERIOD_BYTES] = "period_bytes",
[SNDRV_PCM_HW_PARAM_PERIODS] = "periods",
[SNDRV_PCM_HW_PARAM_BUFFER_TIME] = "buffer_time",
[SNDRV_PCM_HW_PARAM_BUFFER_SIZE] = "buffer_size",
[SNDRV_PCM_HW_PARAM_BUFFER_BYTES] = "buffer_bytes",
[SNDRV_PCM_HW_PARAM_TICK_TIME] = "tick_time",
};
static void param_dump(struct snd_pcm_hw_params *p)
{
int n;
for (n = SNDRV_PCM_HW_PARAM_FIRST_MASK;
n <= SNDRV_PCM_HW_PARAM_LAST_MASK; n++) {
struct snd_mask *m = param_to_mask(p, n);
LOGV("%s = %08x%08x\n", param_name[n],
m->bits[1], m->bits[0]);
}
for (n = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL;
n <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; n++) {
struct snd_interval *i = param_to_interval(p, n);
LOGV("%s = (%d,%d) omin=%d omax=%d int=%d empty=%d\n",
param_name[n], i->min, i->max, i->openmin,
i->openmax, i->integer, i->empty);
}
LOGV("info = %08x\n", p->info);
LOGV("msbits = %d\n", p->msbits);
LOGV("rate = %d/%d\n", p->rate_num, p->rate_den);
LOGV("fifo = %d\n", (int) p->fifo_size);
}
static void info_dump(struct snd_pcm_info *info)
{
LOGV("device = %d\n", info->device);
LOGV("subdevice = %d\n", info->subdevice);
LOGV("stream = %d\n", info->stream);
LOGV("card = %d\n", info->card);
LOGV("id = '%s'\n", info->id);
LOGV("name = '%s'\n", info->name);
LOGV("subname = '%s'\n", info->subname);
LOGV("dev_class = %d\n", info->dev_class);
LOGV("dev_subclass = %d\n", info->dev_subclass);
LOGV("subdevices_count = %d\n", info->subdevices_count);
LOGV("subdevices_avail = %d\n", info->subdevices_avail);
}
#else
static void param_dump(struct snd_pcm_hw_params *p) {}
static void info_dump(struct snd_pcm_info *info) {}
#endif
#define PCM_ERROR_MAX 128
struct pcm {
int fd;
unsigned flags;
int running:1;
int underruns;
unsigned buffer_size;
char error[PCM_ERROR_MAX];
};
unsigned pcm_buffer_size(struct pcm *pcm)
{
return pcm->buffer_size;
}
const char* pcm_error(struct pcm *pcm)
{
return pcm->error;
}
static int oops(struct pcm *pcm, int e, const char *fmt, ...)
{
va_list ap;
int sz;
va_start(ap, fmt);
vsnprintf(pcm->error, PCM_ERROR_MAX, fmt, ap);
va_end(ap);
sz = strlen(pcm->error);
if (errno)
snprintf(pcm->error + sz, PCM_ERROR_MAX - sz,
": %s", strerror(e));
return -1;
}
int pcm_write(struct pcm *pcm, void *data, unsigned count)
{
struct snd_xferi x;
if (pcm->flags & PCM_IN)
return -EINVAL;
x.buf = data;
x.frames = (pcm->flags & PCM_MONO) ? (count / 2) : (count / 4);
for (;;) {
if (!pcm->running) {
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE))
return oops(pcm, errno, "cannot prepare channel");
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x))
return oops(pcm, errno, "cannot write initial data");
pcm->running = 1;
return 0;
}
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) {
pcm->running = 0;
if (errno == EPIPE) {
/* we failed to make our window -- try to restart */
pcm->underruns++;
continue;
}
return oops(pcm, errno, "cannot write stream data");
}
return 0;
}
}
int pcm_read(struct pcm *pcm, void *data, unsigned count)
{
struct snd_xferi x;
if (!(pcm->flags & PCM_IN))
return -EINVAL;
x.buf = data;
x.frames = (pcm->flags & PCM_MONO) ? (count / 2) : (count / 4);
// LOGV("read() %d frames", x.frames);
for (;;) {
if (!pcm->running) {
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE))
return oops(pcm, errno, "cannot prepare channel");
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START))
return oops(pcm, errno, "cannot start channel");
pcm->running = 1;
}
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_READI_FRAMES, &x)) {
pcm->running = 0;
if (errno == EPIPE) {
/* we failed to make our window -- try to restart */
pcm->underruns++;
continue;
}
return oops(pcm, errno, "cannot read stream data");
}
// LOGV("read() got %d frames", x.frames);
return 0;
}
}
static struct pcm bad_pcm = {
.fd = -1,
};
int pcm_close(struct pcm *pcm)
{
if (pcm == &bad_pcm)
return 0;
if (pcm->fd >= 0)
close(pcm->fd);
pcm->running = 0;
pcm->buffer_size = 0;
pcm->fd = -1;
return 0;
}
struct pcm *pcm_open(unsigned flags)
{
const char *dname;
struct pcm *pcm;
struct snd_pcm_info info;
struct snd_pcm_hw_params params;
struct snd_pcm_sw_params sparams;
unsigned period_sz;
unsigned period_cnt;
LOGV("pcm_open(0x%08x)",flags);
pcm = calloc(1, sizeof(struct pcm));
if (!pcm)
return &bad_pcm;
if (flags & PCM_IN) {
dname = "/dev/snd/pcmC0D0c";
} else {
dname = "/dev/snd/pcmC0D0p";
}
LOGV("pcm_open() period sz multiplier %d",
((flags & PCM_PERIOD_SZ_MASK) >> PCM_PERIOD_SZ_SHIFT) + 1);
period_sz = 128 * (((flags & PCM_PERIOD_SZ_MASK) >> PCM_PERIOD_SZ_SHIFT) + 1);
LOGV("pcm_open() period cnt %d",
((flags & PCM_PERIOD_CNT_MASK) >> PCM_PERIOD_CNT_SHIFT) + PCM_PERIOD_CNT_MIN);
period_cnt = ((flags & PCM_PERIOD_CNT_MASK) >> PCM_PERIOD_CNT_SHIFT) + PCM_PERIOD_CNT_MIN;
pcm->flags = flags;
pcm->fd = open(dname, O_RDWR);
if (pcm->fd < 0) {
oops(pcm, errno, "cannot open device '%s'");
return pcm;
}
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_INFO, &info)) {
oops(pcm, errno, "cannot get info - %s");
goto fail;
}
info_dump(&info);
LOGV("pcm_open() period_cnt %d period_sz %d channels %d",
period_cnt, period_sz, (flags & PCM_MONO) ? 1 : 2);
param_init(¶ms);
param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS,
SNDRV_PCM_ACCESS_RW_INTERLEAVED);
param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_FORMAT,
SNDRV_PCM_FORMAT_S16_LE);
param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_SUBFORMAT,
SNDRV_PCM_SUBFORMAT_STD);
param_set_min(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, period_sz);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 16);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_FRAME_BITS,
(flags & PCM_MONO) ? 16 : 32);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_CHANNELS,
(flags & PCM_MONO) ? 1 : 2);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS, period_cnt);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_RATE, 44100);
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_HW_PARAMS, ¶ms)) {
oops(pcm, errno, "cannot set hw params");
goto fail;
}
param_dump(¶ms);
memset(&sparams, 0, sizeof(sparams));
sparams.tstamp_mode = SNDRV_PCM_TSTAMP_NONE;
sparams.period_step = 1;
sparams.avail_min = 1;
sparams.start_threshold = period_cnt * period_sz;
sparams.stop_threshold = period_cnt * period_sz;
sparams.xfer_align = period_sz / 2; /* needed for old kernels */
sparams.silence_size = 0;
sparams.silence_threshold = 0;
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SW_PARAMS, &sparams)) {
oops(pcm, errno, "cannot set sw params");
goto fail;
}
pcm->buffer_size = period_cnt * period_sz;
pcm->underruns = 0;
return pcm;
fail:
close(pcm->fd);
pcm->fd = -1;
return pcm;
}
int pcm_ready(struct pcm *pcm)
{
return pcm->fd >= 0;
}